Red blood cell formation, DNA synthesis, and neuron function all depend on vitamin B12. For individuals with B12 deficiency, injections are a common and effective treatment option. In addition to treating deficiencies, some people also explore IV Hydration and vitamin B12 injections for weight loss, although this use is still being researched. https://www.vital-flo.com/post/how-to-give-a-b12-injection